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Constraints question (by Bill Lugg)
OK, here's my first newby question regarding applying constraints. In the attached file, which will be a model of a wall with a trapezoidal cross section, I know the outside length of the wall, the included angle of the edges of the wall and the thickness. When I try to place a vertical distance constraint for the thickness, SolveSpace wants to place a distance between the points.
I figured I could construct a vertical construction line between one of the inner vertices and the outer edge of the wall and use those points for my dimension, but SolveSpace complains that it cant solve.
What am I missing?
Also, you'll notice a dimension centering the wall on the working plane. I tried to use the Symetric constraint selecting the two end points of the outer edge and selecting the constraint, but SolveSpace complained of redundant constraints (this was the first constraint I tried to apply). So I'm not sure what I'm doing wrong there either.
Thanks for the help.
Bill Lugg
I figured I could construct a vertical construction line between one of the inner vertices and the outer edge of the wall and use those points for my dimension, but SolveSpace complains that it cant solve.
What am I missing?
Also, you'll notice a dimension centering the wall on the working plane. I tried to use the Symetric constraint selecting the two end points of the outer edge and selecting the constraint, but SolveSpace complained of redundant constraints (this was the first constraint I tried to apply). So I'm not sure what I'm doing wrong there either.
Thanks for the help.
Bill Lugg
(no subject) (by Ektor)
for your example there are two ways to do it.
(to my knowledge).
1/ select the right
2/ select the point
3/ constraint > distance
https://i.ibb.co/Kzwb8Wk/01.jpg
or
1/ choose the first point
2/ choose the second point
3/ click on the direction arrow (here the Z axis, green)
4/ enter the distance
https://i.ibb.co/8rsvTMj/02.jpg
(no subject) (by cmpxchg)
Perhaps the H and V labels / constraints automatically added by the userinterface create an overconstraint situation. You can remove the purple H and V constraint by clicking carefully.
Not that there is a checkbox in each group to 'allow redundant constraints' that is by default off.
Checking it can help resolving unresolvable sketches, but use of it should be with care. Solvespace workflow tries to encourage describing the object with as few variables as possible.
Not that there is a checkbox in each group to 'allow redundant constraints' that is by default off.
Checking it can help resolving unresolvable sketches, but use of it should be with care. Solvespace workflow tries to encourage describing the object with as few variables as possible.
(no subject) (by Paul)
For thickness you might select a point and a line, then press d. A point-line distance constraint will work even if the point is beyond the end of the line.
(no subject) (by Bill Lugg)
Thanks for the pointer. The point and a line solution worked well.
As for the symmetry issue, I tried removing the two Horizontal constraints and then applying the Symmetric constraint to the end points of the outer edge, which worked. However, it left me with one DOF that I couldn't figure out, so I stuck with what I had.
One puzzling thing was that even though I have Coincident constraints at the end points of the inner edge where it joins the ends of the wall, SolveSpace lets me drag it off those point and then indicate a constraint violation. I would have thought it would have kept everything joined, and if the line is fixed by the constraints on it, it just wouldn't allow it to move. Admittedly, my background is in FreeCAD and this is how it works, so I have to get used to a new application.
Thanks again.
Bill Lugg
As for the symmetry issue, I tried removing the two Horizontal constraints and then applying the Symmetric constraint to the end points of the outer edge, which worked. However, it left me with one DOF that I couldn't figure out, so I stuck with what I had.
One puzzling thing was that even though I have Coincident constraints at the end points of the inner edge where it joins the ends of the wall, SolveSpace lets me drag it off those point and then indicate a constraint violation. I would have thought it would have kept everything joined, and if the line is fixed by the constraints on it, it just wouldn't allow it to move. Admittedly, my background is in FreeCAD and this is how it works, so I have to get used to a new application.
Thanks again.
Bill Lugg
(no subject) (by Paul)
Points-coincident constraints are almost never violated in my experience. Only when the solver fails and the background turns red.
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